Question on Re-Jetting a 2004 883 Sportster

I have a 2004 883 custom sportster and have changed the mufflers to screamin eagle ll and have also changed the air filter to a SEll high flow. I know I have to re-jet the carbs but I have been getting a lot of different answers. Some say to only change the main to a 170 and others say to change both. Has anybody out there been thru this? I want to get it right the first time. Any responses would be greatly appreciated. Thanks